Results Of Amniotic Membrane Transplantation Research Articles

Amniotic membrane grafts for nontraumatic corneal perforations, descemetoceles, and deep ulcers

PurposeTo describe the clinical outcome of amniotic membrane transplantation (AMT) for nontraumatic corneal perforations, descemetoceles, and deep ulcers. DesignRetrospective, noncomparative, interventional case series. ParticipantsThirty-four eyes of 33 consecutive patients operated on for nontraumatic corneal perforations or descemetoceles at four academic departments of ophthalmology. Associated autoimmune disorders included rheumatoid arthritis (n = 6), Stevens-Johnson syndrome (n = 3), ocular cicatricial pemphigoid (n = 2), systemic lupus erythematosus (n = 1), and one eye with Mooren’s ulcer, as well as neurotrophic, or exposure keratopathy (n = 10), postinfectious nonhealing ulcers (n = 6), and postsurgery (n = 5). InterventionThree or four layers of amniotic membrane (AM) were applied over the ulcer bed and anchored with 10-0 nylon interrupted or running sutures. A large AM piece was used as a patch to cover the entire corneal surface. Main outcome measuresFormation of anterior chamber depth, epithelialization of the AM grafts, and stability of the corneal stromal thickness. ResultsThe mean follow-up period was 8.1 ± 5.7 (ranging from 2–23) months. A successful result was observed in 28 of 34 eyes (82.3%). Of the successful cases, 23 eyes needed one AMT procedure, whereas 5 eyes needed two procedures to achieve a successful result. In five eyes, a subsequent definitive surgical procedure such as penetrating keratoplasty or lid surgery was needed. Failure was observed in six eyes with rheumatoid arthritis, neurotrophic keratopathy, or graft melting. ConclusionsAMT is an effective method for managing nontraumatic corneal perforations and descemetoceles. It can serve as either a permanent therapy or as a temporizing measure until the inflammation has subsided and a definitive reconstructive procedure can be performed. This treatment option is also beneficial in those countries where corneal tissue availability is limited.

Amniotic membrane transplantation for partial limbal stem cell deficiency

AIMTo examine the efficacy, safety, and long term outcomes of amniotic membrane transplantation for corneal surface reconstruction in cases of partial limbal stem cell deficiency.METHODS17 eyes of 15 patients with...

Suppression of transforming growth factor-beta isoforms, TGF-beta receptor type II, and myofibroblast differentiation in cultured human corneal and limbal fibroblasts by amniotic membrane matrix.

Down-regulation of the transforming growth factor-beta (TGF-beta) signaling system is a strategy for preventing scarring during wound healing. Human corneal and limbal fibroblasts were cultured on the stromal matrix side of preserved human amniotic membrane. The levels of TGF-beta1, beta2, and beta3 and TGF-beta type II receptor transcripts and TGF-beta1 and beta2 proteins were suppressed as early as 8 hr and more dramatically at 24 hr after contact with an amniotic membrane. This suppressive effect was accompanied by down-regulation of alpha-smooth muscle actin, EDA spliced form of fibronectin, and integrin alpha5. It persisted even when challenged by 10 ng/ml TGF-beta1. In contrast with their counterparts grown on plastic or in collagen gel, such suppression in amniotic membrane cultures remained complete after 1 week of culturing. Cells cultured on amniotic membrane showed significantly reduced [3H]-thymidine incorporation compared to cells cultured on plastic and displayed no DNA fragmentation. These results reveal a novel mechanism by which the TGF-beta signaling system, DNA synthesis, and subsequent myofibroblast differentiation can be suppressed by an amnionic membrane matrix. This action explains in part the antiscarring results of amniotic membrane transplantation used for ocular surface reconstruction, a surgical technique applicable to other subspecialties. It may also explain in part why fetal wound healing is scarless.